Window screen alarm



June 15,, 1948, DQQLEY 24 E353? WINDOW S GREEN ALARM Filed June 25, 12.146

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ATTQFINE'Y Patented June 15, 1948 WINDOW SCREEN ALARM John T. Dooley, Buffalo, N. Y., assignor to James J. Dooley, Buffalo, N. Y.

Application June 25,, 1946, Serial No. 679,114

6 Claims. (Cl. 200-52) This invention relates generally to certain new and useful improvements in burglar alarms but more particularly to an electrically-operated alarm device designed for use on window screens and the like.

It has for one of its objects to provide a simple, compact and inexpensive device of this character which is in the form of a self-contained switch control unit and can be readily attached to a window screen or the like and as readily connected in circuit with a suitable alarm device, such as a bell.

Another object of the invention is to so design and construct the device that it will be automatically rendered operative to sound the alarm should the screen be tampered or meddled with in any way by unauthorized persons, as for example, attempting to remove or swing the screen bodily open or cutting the screen cloth and then attempting to enter the premises therethrough.

Other features of the invention reside in the construction and arrangement of parts hereinafter described and particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is an inside view of a room showing my invention installed in association with the window screen thereof. Figure 2 is a fragmentary perspective view of a window screen showing my self-contained circuit control unit applied thereto. Figure 3 is an enlarged fragmentary vertical section showing the screen in place in the window frame and the switch control unit in its operative position in readiness to sound the alarm if the screen should be tampered with. Figure 4 is a similar view, but with the screen detached or about to be installed in the window frame, showing the position the parts assume under such condition. Figure 5 is an enlarged vertical section taken on line 5-5, Figure 2. Figure 6 is a diagrammatic view of the electric circuit of the alarm device.

Similar characters of reference indicate the corresponding parts throughout the several views.

Referring now to the drawings, Ill indicates a window frame and l l a window screen of ordinary construction which is removably mounted in the frame. My device is adapted to be attached as a self-contained unit on the top or other portion of the screen in the manner shown in Figure l and consists of a supporting plate or member l2 of insulating material secured to an outer edge of the screen by screws I3, and having opposing yieldable switch blades or contact members l4 and i5 applied thereto and included in an electric circuit I6 having a bell or like alarm l1 included therein. The switch blades are so disposed as to assume a plurality of difierent positions relative to each other to assure a closing of the alarm circuit should the screen be tampered with in any way, and for this purpose one of the switch blades I4 is adapted atone time to make contact at two spaced points with the companion blade I5 as shown in Figure 4, another time to make contact at one point with such companion blade as shown in Figure 6, while in a third position, shown in Figure 3, the switch blade I5 is adapted to be tensioned by a string or cord. I 8, clear of both contacts, the cord extending adjacent the inner side of the cloth of the screen. This cord is secured at one end to the switch blade [5 and at its other end to a portion of the window frame as shown in Figure 1, to hold such blade clear of the two contact points on the companion blade until such time as the cord should be disturbed, cut or strained in any way, which would then cause the switch blades to make contact and close the alarm circuit.

The contact blades l4, [5 are suitably attached at their outer ends to the underside of the plate [2 and their opposing contacting inner ends are free to yield to assume the normally expanded position shown in Figure 4, the screen I I having a recess 19 therein and the plate having a companion registering opening 20 therein into and through which the blades may enter and pass as required. The blade [4 has a depressible portion 2| terminating at its lower end in an open loop-like throat 22 into which the tongue 23 of the companion blade l5 extends and which provides spaced contacts 24, 25 with either or both of which such blade-tongue is adapted to make contact as seen in Figures 3, 4, and 6. In the pre-set position of the alarm, shown by full lines in Figure 3, the cord l8 retains the blade-tongue 23 out of contact with both blade-contacts 24, 25. in any manner, as by one attempting to gain entrance to the house through the screen, then the However, should this cord be cut or strained blade-tongue 23 will engage one or the other oi! the contacts 24, 25 and close the alarm circuit.

For the purpose of facilitating the circuit connection between the unit and the alarm and making such connection automatically when the screen is installed in the window frame, I provide the contact-bearing plate with a post 26 rising therefrom and adapted to laterally engage one of the contacts 21 of a jack fitting 28 applied to the window frame in the manner shown in Figure 4. This fitting has two lead wires 29, 30 connecting the circuit to a source of power, the wire 29 being connected to the fixed contact 21 and the companion wire 30 being in conducting relation to a yieldable contact 3| adapted in one position to abut the end of the post 26 in the manner shown in Figure 3, and in its other posi- J tion, shown in Figure 4, to abut that part of the jack fitting connected to the wire 29. The outer side portion of the post engages th fixed contact 21 and insulated from it and extending therethrough is a stem 32 terminating at its upper end in a head 33 for abutting engagement with the lower end of the yieldable contact 3|. The outer post portion is electrically connected to theswitch blade l5 and the inner post portion or stem 32 is connected to the companion switch blade M. A spring 34 applied to the yieldable contact. 3i serves to normally urge the latter to the position shown in Figure 4, so that when the screen is out, the alarm circuit is directly established across the jack fitting. In the installed position of the screen the alarm circuit is controlled by the switch blades I4, I 5. When the screen is removed, the yieldable contact 3| assumesthe position shown in Figure 4 with the alarm circuit closed directly across the jack fitting 28.

I claim as my invention:

. 1,. In a burglar alarm device of the character described, a plate adapted for attachment to a window screen or the like, a pair of yieldable contact members applied to said plate for inc1u-. sion in an alarm circuit and adapted for relative movement into and out of contacting relation, one of said members having dual contact portions and being normally depressed undertension, in the installed position of the screen, to bring one of its contact portions out of contacting relation with the companion member while maintaining its other portion in contact with such companion member, and means attached to said companion member for normally exerting a tension thereon to bring it out of contacting relation with the second-named portion of said first-named member.

2. In a burglar alarm device of the character described, a plate adapted for attachment to a window screen or the like, a pair of yieldable contact members applied to said plate for inclusion in an alarm circuit'and adapted for relative movement into and out of contacting relation, said members being disposed in opposing contacting relation with one member terminating in an open loop to provide spaced contacting portions and the companion member extending at its free end into such open loop to contact either one or both of its contact portions, said loop bearing member being normally depressed under tension, in the installed position of the screen or the like, to bring one of its loopierming contact portions out of contact with the companion member while maintaining its other contact portion in contact with such member, and meansattached to said companion member for 4 normally exerting a tension thereon to bring it out of contact with the second-named loop-forming contact portion of said first-named member. 3. In a device of the character described, a supporting plate having an opening therein, and opposing yieldable contact members attached at their outer ends to said plate and having their inner free ends in register with the plate-opening for relative displacement therein, one of said members having a depressible portion normally projecting beyond one sideof the plate and terminating at its free end in an open-loop-like throat providing spaced contacts and the companion member having a portion projecting beyond the opposite side of the plate and terminating at its free end in a tongue extending into said loop-like throat for engagement jointly with the spaced contacts thereof, said first-named member when depressed bringing one of its contacts out of engagement with the tongue of said companion member while maintaining engagement of its other contact with such tongue, the companion member being adapted to be displaced 1 under tension to bring its tongue out of engagement with such other contact of the loop-like throat in said first-named member.

4. In a device of the character described, a supporting plate having an opening therein, and opposing yieldable contact members attached at their outer ends to said plate and having their inner free ends in register with the plate-opening for relative displacement therein, one of said members including an open, loop-like throat at its free end to provide spaced contact points and the companion member including a tongue extending into said throat for joint contact with both of said spaced contact points in one position of said members, for contact with one of such points in another position of said members, and in a third position of said members to assume a position clear of such contacts.

5. In a burglar alarm device of the character described, a plate adapted for attachment to a window screen or the like, a pair of yieldable contact members applied to said plate for inclusion in an alarm circuit and adapted for relative movement into and out of contacting relation, one of said members having dual contact portions and being normally depressed under tension in the installed position of the screen, to bring one of its contact portions out of contacting relation with the companion member while maintaining its other portion in contact with such companion member, means attached to said companion member for normally exerting a tension thereon to bring it out of contacting relation with the second-named portion of said firstnamed member, a contact post rising from said plate and included in the circuit of said contact members, and companion contacts in the circult applied to the window frame and with which said contact "post is adapted to engage in the installed position of the screen.

6. In a burglar alarm device of the character described, a plate adapted for attachment to a window screen or the like, a pair of yieldable contact members applied to said plate for inclusion in an alarm circuit and adapted for relative movement into and out of contacting relation, one of said members having dual contact portions and being normally depressed under tension in the installed position of the screen, to bring one of its contact portions out of contacting relation with the companion member While maintaining its other portion in contact with such companion member, means attached to said companion member for normally exerting a tension thereon to bring it out of contacting relation with the second-named portion of said firstnamed member, a contact post rising from said plate and included in the circuit of said contact members, and companion contacts in the circuit applied to the window irame and with which said contact post is adapted to engage in the installed position of the screen, one of said frame-contacts being fixed and the other being yieldable for abutting contact with said post.

JOHN T. DOOLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

